In a stunning, late-breaking Iowa caucus turnabout, the state chairman for presidential candidate Michele Bachmann ditched her campaign Wednesday night to endorse Ron Paul, a rival in the race for the GOP nomination.

Kent Sorenson

The defection of Kent Sorenson, an Iowa state senator, came just six days before Iowa’s first-in-the-nation caucuses, and caught the Bachmann campaign by surprise. Sorenson had chaired Bachmann’s caucus efforts here for months, and even attended a Bachmann event in Indianola on Wednesday afternoon just hours before appearing at a Paul rally in Des Moines to announce his endorsement.

“I believe we’re at a turning point in this campaign,” Sorenson said in his announcement at the Paul rally “… I thought it was my duty to come to his aid, just like he came to my aid during my Senate race, which was a very nasty race.”

Sorenson, an Indianola Republican, was elected to the state Senate in 2010 with support from Paul and his legion of Iowa backers. His announcement was greeted with sustained applause from a crowd of roughly 500.

Many rose to their feet and hoisted Paul campaign signs above their heads when Sorenson added: “We’re going to take Ron Paul all the way to the White House.”

Sorenson told the Register he had been thinking about supporting Paul for a couple of days, but that he didn’t make the decision to switch campaigns until Wednesday evening. Sorenson said he drove to Paul’s 7 p.m. event, called a Paul staffer and asked: “Do you guys want me on board?”

Sorenson declined to talk about the Bachmann campaign, instead saying he was basing his decision on the strength of Paul’s efforts in Iowa.

“The fact of the matter is that I believe we have a clear, top-tier race between Romney and Ron Paul,” Sorenson said, asserting that the “Republican establishment” was unfairly biased against the congressman’s bid for office.

“We have a choice where we can elect more of the same … or we can elect someone who’s going to transform this country to get it back to what our founding fathers wanted, and I believe that’s Ron Paul,” he said.

Sorenson gave little hint of his looming exit during an appearance with Bachmann at an event Wednesday in Indianola. He walked with her as she met voters at the Pizza Ranch there.

Upon learning of Sorenson’s announcement hours later, Bachmann struck back with a sharply worded statement accusing him of selling his endorsement to a higher bidder.

“Kent Sorenson personally told me he was offered a large sum of money to go to work for the Paul campaign,” Bachmann said in a hastily arranged press conference outside a Pizza Ranch in Boone, where she held her 11th campaign event of the day.

“Kent campaigned with us earlier this afternoon and went immediately afterward to a Ron Paul event and announced he is changing teams,” Bachmann continued. “Kent said to me yesterday that ‘Everyone sells out in Iowa, why shouldn’t I?’ then he told me he would stay with our campaign.”

Bachmann did not take questions, but continued meeting with voters and making her pitch for support in Tuesday’s caucuses.

Members of her campaign were visibly distraught, however. Bachmann spokeswoman Alice Stewart disputed reports that Sorenson called the campaign to inform staffers of his defection.

“We found out about it when we started getting requests from the media for response,” Stewart said.

Paul has surged to the top of the polls in Iowa and is sprinting toward the caucuses with substantial TV ad buys, while Bachmann has remained mired in the high-single digits and pinned her hopes on a bus tour of all 99 Iowa counties.